Link aggregation or trunking enables the connection of two networked devices, such as network devices, computers, end stations, etc., by grouping multiple physical network links between the devices into a single logical link. For example, administrators of a network aggregate several Ethernet links together into a link aggregation group (LAG) or trunk as defined in the IEEE 802.1ax standard. By setting up a LAG based on these standards, the network appears to run on a single Media Access Controller (MAC) that distributes the Ethernet packets among the physical links in the LAG.
Link aggregation provides for greater redundancy, such that if one of the physical network links fails, another physical network link of the same logical link may be used. Additionally, grouping multiple physical network links may increase the bandwidth capacity of the communication channel between the two devices and provides load balancing over the physical links that are grouped together.